All human action have one or more of these Seven causes :
Chance, Nature, Compulsion, Habit, Reason, Passion & Desire.
All the other six, except Chance, are related internally to the person and those who are dependent on factors that can be controlled.
Astha is an opportunity which keeps knocking at your door. The key lies in recognizing this chance and converting it into once-in-a-lifetime prospect. A wise man turns chance into good future.